I'm guessing it's because they are adding the /C at the time of invoicing and not on the SO itself. With the new feature to be able to invoice multiple SO's on one invoice, it sorts the lines (whether you have that new group in your report or not) by the SO number. Since the /C was added in Invoice Data Entry, there is no SO number on that line, therefore it prints it first. If they don't plan to use the new feature you can add a group #4 off the LineSeqNo so it prints in the order they are in SO Inv entry. Just FYI that the .rpt you attached isn't the latest and greatest version of the invoice form. The new one adds a group to print the SO number and Cust PO number from the SO.